That's why Brown's campaign sent a letter to Munger this week, pleading for restraint and saying that attack ads "could cause irreparable harm to our students and schools."

The letter took a pointed jab, saying, "The Munger family could be known as the millionaires who destroyed California's schools and universities."

Molly Munger has given more than $30 million to her Prop 38 campaign, while her brother, Charles Munger, has contributed over $23 million to a campaign committee that is also targeting Gov. Brown's measure for defeat.

That plea to hold off on attack ads didn't work, prompting this assessment from Brown advisor Steve Glazer on Twitter: "Circular firing squad is in position with the kids in the middle."

Prop 30, Brown's measure, seeks to impose a temporary quarter cent sales tax and a temporary income tax hike on high-income Californians in order to avoid deep "trigger cuts" to schools of more than $5 billion.

By contrast, Munger's measure would raise the income tax on almost all working Californians for school funding.

Munger's ad takes aim at the fact that lawmakers could reduce school spending in the state's general fund to offset the new money Prop 30 would generate for schools. The ad uses a time-honored tactic of capitalizing on distrust for Sacramento, saying, "Don't be misled by the politicians."

Munger believes in her measure so much that she's been willing to spend huge amounts of her own fortune.

But the attack ads unveiled Tuesday represent what the Brown team thought to be unthinkable..a launch of nuclear war where nobody wins.